Of course, early .45-70 loads were hampered not only by the black powder, but also the Trapdoor Springfield action and the soft "balloon head" copper cartridge cases with their Benét internal primers. The early cases were formed much like an oversized .22 LR; however, the firing pin struck the center of case head to ignite the internal primer. Frankford Arsenal would not begin mass producing .45-70 cartridges with Berdan external primers until 1882, and copper cased cartridges were still produced as late as 1888.